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arXiv · 1311.7389

Partial preservation of chiral symmetry and colossal magnetoresistance in adatom doped graphene

Gonzalo Usaj·Pablo S. Cornaglia·C. A. Balseiro
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Abstract

We analyze the electronic properties of adatom doped graphene in the low impurity concentration regime. We focus on the Anderson localized regime and calculate the localization length ($ξ$) as a function of the electron doping and an external magnetic field. The impurity states hybridize with carbon's $p_z$ states and form a partially filled band close to the Dirac point. Near the impurity band center, the chiral symmetry of the system's effective Hamiltonian is partially preserved which leads to a large enhancement of $ξ$. The sensitivity of transport properties, namely Mott's variable range hopping scale $T_0$, to an external magnetic field perpendicular to the graphene sheet leads to a colossal magnetoresistance effect, as observed in recent experiments.

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Gonzalo Usaj, Pablo S. Cornaglia, C. A. Balseiro. 2014-01-27. Partial preservation of chiral symmetry and colossal magnetoresistance in adatom doped graphene. https://doi.org/10.1103/physrevb.89.085405

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